Head Porting How-To
#1
Head Porting How-To
http://www.sa-motorsports.com/diyport.shtm
I know a bunch of you guys wish you could have ported heads but the price tag is prohibitive. Here's a way to start. Grab a set of Non-PI heads and whittle away at them using the info in the article above. Once you've gotten the patience and design down, grab a set of PI heads and go to work. Then take them down to your local race shop and have them flow benched. If they're better, they're better right. if not, at least you didn't lose much.
Enjoy.
I know a bunch of you guys wish you could have ported heads but the price tag is prohibitive. Here's a way to start. Grab a set of Non-PI heads and whittle away at them using the info in the article above. Once you've gotten the patience and design down, grab a set of PI heads and go to work. Then take them down to your local race shop and have them flow benched. If they're better, they're better right. if not, at least you didn't lose much.
Enjoy.
#2
I am thinking about, instead of ordering some heads like say patriot performance stage 3, I could just port match my intake and exhaust ports. Would that gain much power? A guy told me I could get 30 horse from matching the ports to the gaskets. Isnt that pretty much all porting is? I know the aftermarket ones have polished bowls and bigger valves but is it worth it? Ill be adding some springs too. Seems like something I could do in a few hours with a good dremel in the backyard....
#3
30hp from port matching is ludicrous. The mouth of the ports isn't even the biggest restriction... it's right before you get to the valve on the short radius turn. There's a couple hard angles that need to smoooth out, also need some smoothing and tapering of the valve guide boss and guide, and some in the bowl. And it's a lot less removal than you might think.
Nonetheless, porting is the first thing you'll need to do to get more out of the heads. Once you improve flow there, then intakes, cams, blowers, nitrous...etc, all have better returns.
BTW, stage 3 are best left on track only cars. Stage II is plenty, besides 3 isn't much of an upgrade in flow over 2. This is also not the domain of a dremel. Use an air powered die grinder. Dremels are too fast and too weak. It'll take days and burn out the dremel.
Nonetheless, porting is the first thing you'll need to do to get more out of the heads. Once you improve flow there, then intakes, cams, blowers, nitrous...etc, all have better returns.
BTW, stage 3 are best left on track only cars. Stage II is plenty, besides 3 isn't much of an upgrade in flow over 2. This is also not the domain of a dremel. Use an air powered die grinder. Dremels are too fast and too weak. It'll take days and burn out the dremel.
#4
Sweet info! I thought about the stage 3 heads at one point, but i was told it was overkill and track only, so that's good you found that out. I was told if you port just the bowls that you could get about 10HP and some TQ, but yeah a dremel would take forever. I ported a TB for a friend with my dremel and it took 2 days and several hours a day to do just that. but i wanted it to look good also. If you have the time and paitence, then porting is good for you, and less expensive....
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audikillsbmw
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11-12-2008 01:29 PM